Individuals infected with the human immunodeficiency virus, type 1 (HIV-1) are at a 60-100 fold increased risk of developing lymphoma as compared to the general population. This risk is likely to increase as a result of improvements in supportive care for opportunistic infections and use of antiretroviral therapy (Gill, P. S. et al. (1987) J. Clin Oncol. 5:1322; Gail, M. H., et al. (1991) J. Natl. Cancer Inst. 83695).
The majority of HIV-associated lymphomas are of B-cell origin and constitute a heterogeneous group of lymphomas (Shiramizu, B. T. et al. (1992) J. Clin. Oncol. 10:383; Levine A. M. et al. (1991) Cancer 68:2466). Primary lymphomas arising in the central nervous system (CNS) typically occur in HIV-1 infected individuals with advanced disease who have had multiple opportunistic infections and have few peripheral CD4+ lymphocytes; the majority of these lymphomas are monoclonal and infected with Epstein-Barr virus (EBV). In contrast, lymphomas arising outside of the CNS often occur in HIV-1 infected individuals who are relatively more immunocompetent and who often have had no prior opportunistic infections. Of these peripheral lymphomas, 30% are polyclonal and lack evidence of EBV infection.
A rare and unique subset of HIV-1 associated lymphomas arising only in body cavities (i.e., peritoneal, pleural, pericardial) has been described (Walts, A. E. et al. (1990) J. Clin. Pathol. 94:170; Knowles, D. M. et al. (1989) Blood 73:792; Chadburn, A. et al. (1993) Cancer 72:3078; Green, I. et al. (1995) Modern Pathol. 8:39). These body cavity based (BCB) lymphomas display a marked propensity for invasion of the pleural or peritoneal cavities where they grow as ascites tumors.
Recently, viral sequences from human herpesvirus, type 8 (HHV-8) were found in six BCB lymphomas (Cesarman, E. et al. (1995) N. Engl. J. Med. 332:1186). HHV-8 is a virus originally discovered in association with Kaposi's sarcoma (KS) in HIV-infected individuals (Moore, P. S. and Chang, Y. (1995) New Engl. J. Med. 332:1181-1185). However, there has been no systematic description of the clinical features, management and outcomes of patients with HIV-associated BCB lymphomas.
In view of the association of a human herpesvirus type 8 with an AIDS-associated BCB lymphoma, there is a need for a cell line containing the human herpesvirus type 8 virus, and from which virus particles can be isolated. This convenient source of a novel virus would allow the generation of antibodies against the agent, screening of a patient or blood supplies for the virus or for antibodies to the virus, and lead to possible preclinical treatment of disease associated with the viral agent.